ObjectiveTo discuss the effect ofβ2 adrenoceptor on the alveolar fluid clearance (AFC) of the rats with severe acute pancreatitis (SAP). MethodsSD rats was made to SAP model by injecting taurocholate into biliary-pancreatic duct.These rats were randomly divided into sham operation group and SAP group, the SAP group was divided into subgroups of SAP-4 h and SAP-24 h according to the sampling time after making model.The wet-to-dry ratio, AFC, and AFC affected byβ2 adrenoceptor agonist-terbutaline or inhibitor-propranolol were measured in the bilateral lungs.β2 adrenoceptor mRNA expression in the lungs tissues was measured by real-time-PCR. ResultsCompared with the sham operation group, the wet-to-dry ratio was significantly decreased (P < 0.05) and the AFC was significantly increased in the subgroup of SAP-4 h or SAP-24 h (P < 0.05), β2 adrenoceptor agonist-terbutaline couldn't increase the AFC of the subgroup of SAP-4 h or SAP-24 h (P > 0.05), inhibitor-propranolol could decrease AFC of subgroup of SAP-4 h or SAP-24 h (P < 0.05).β2 adrenoceptor mRNA was decreased in the subgroup of SAP-4 h or SAP-24 h as compared with the sham operation group (P < 0.05). ConclusionsBilateral lung liquid volome induced by SAP is less than the normal lung, AFC is increased in the early period of SAP but decreased in the late period.when the lung injury happens, β2 adrenoceptor might modulate AFC in rats of SAP model.The mechanism of lung injury of SAP is so complex that we need more experiments to be done.